Drug Use and Exercise

Doses of insulin and oral hypoglycemics in diabetics may need to be adjusted (according to the amount of anticipated exercise) to prevent hypoglycemia during exercise. Exercisers with non-insulin-dependent diabetes benefit from an exercise-induced increase in insulin sensitivity, facilitating uptake of glucose by muscle.

Doses of drugs that can cause orthostatic hypotension (eg, antidepressants, antihypertensives, hypnotics, anxiolytics, diuretics) may need to be lowered to avoid exacerbation of orthostasis by fluid loss during exercise, leading to presyncope or syncope. For patients taking such drugs, adequate fluid intake is essential during exercise.

Some sedative-hypnotics may reduce physical performance, either indirectly by decreasing activity levels or directly by inhibiting effects on muscles and nerves. These and other psychoactive drugs increase the risk of falls. Discontinuing such drugs or reducing their dose may be necessary to improve the safety of exercise and to increase patient adherence.

When -blockers are used, endurance intensity cannot be monitored by the target heart rate method. These drugs may mask hypoglycemic symptoms other than sweating.

Drugs with anabolic activity (eg, growth hormone, estrogen, testosterone, vitamins) have long been suggested as a means to build muscle mass in elderly patients with sarcopenia. However, studies with exogenous growth hormone have shown mixed results; some have not found an effect on muscle strength, even when combined with muscle-strengthening exercises. Evidence about the effect of estrogen replacement on muscle strength is limited and inconsistent. Testosterone replacement in hypogonadal men appears to increase muscle strength; however, dose-response information is lacking and adverse effects (eg, prostate cancer) are a concern. There is little evidence for or against a role of vitamins in improving muscle strength, although one study showed that vitamin D has no effect.